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241.
Sudaryanto A Kajiwara N Tsydenova OV Isobe T Yu H Takahashi S Tanabe S 《Chemosphere》2008,73(10):1661-1668
Fourteen PBDE congeners from mono- to deca-BDE were determined in breast milk of primiparous mothers from two locations in East China, i.e. Nanjing (n=9), an urban area, and Zhoushan (n=10), a semi rural coastal area. PBDEs were detected in all the human breast milk samples of the present study, indicating that general population in these two locations are widely exposed to these pollutants. Relatively higher concentrations of PBDEs were found in the milk of mothers from Nanjing than Zhoushan, suggesting the existence of significant sources of PBDEs in urban areas. PBDE levels in the present study were similar to those in European countries, but one or two orders of magnitude lower than in North America. Except for BDE-3, all congeners from di- to deca-BDE were detected in the samples of the present study. BDE-209, a congener considered to have less bioavailability, was detected in about 50% of the samples at concentrations higher than that of other congeners. Other higher brominated congeners, such as BDE-153, -197 and -207, were also prominent in the present study, which is different from the pattern generally observed in previous studies on human milk as well as biota samples. These results may indicate that the inhabitants of Nanjing and Zhoushan are exposed to location specific sources of PBDEs. 相似文献
242.
Sudaryanto A Kajiwara N Takahashi S Muawanah Tanabe S 《Environmental pollution (Barking, Essex : 1987)》2008,151(1):130-138
The present study reports concentrations of polybrominated diphenyl ethers (PBDEs) and organochlorines (OCs) in human breast milk from Indonesia covering urban, suburban and rural areas. PBDEs were detected in all the samples of the present study with total concentrations ranging from 0.49 to 13 ng/g lipid wt. Geographical distribution showed that concentrations of PBDEs were relatively uniform (p>0.05) and the levels were in the same order as those in Japan and some European countries, but were one or two order lower than North America. When compared to OCs, the level of total PBDEs was lower. The congener pattern was in accordance with other studies on human matrices, in which BDE-47 was the most abundant congener. Variations of PBDE congeners in human breast milk were further discussed to elucidate the potential exposure source(s) and pathways. 相似文献
243.
Nobuo Kokubun Akinori Takahashi Yoshihisa Mori Shinichi Watanabe Hyoung-Chul Shin 《Marine Biology》2010,157(4):811-825
Chinstrap, Pygoscelis antarctica, and gentoo, P. papua, penguins are sympatric species that inhabit the Antarctic Peninsula. To evaluate differences in the foraging habitat of
these two species, we recorded their foraging locations and diving behavior using recently developed GPS-depth data loggers.
The study was conducted on King George Island, Antarctica during the chick-guarding period of both species, from December
2006 to January 2007. The area used for foraging, estimated as the 95% kernel density of dive (>5 m) locations, overlapped
partially between the two species (26.4 and 68.5% of the area overlapped for chinstrap and gentoo penguins, respectively).
However, the core foraging area, estimated as the 50% kernel density, was mostly separate (12.8 and 25.0% of the area overlapped
for chinstrap and gentoo penguins, respectively). Chinstrap penguins tended to use off-shelf (water depth > 200 m) regions
(77% of the locations for dives >5 m), whereas gentoo penguins mainly used on-shelf (water depth < 200 m) areas (71% of dive
locations). The data on foraging locations, diving behavior, and bathymetry indicated that gentoo penguins often performed
benthic dives (28% of dives >5 m), whereas chinstrap penguins almost always used the epipelagic/mid-water layer (96% of dives
>5 m). Diving parameters such as diving bottom duration or diving efficiency differed between the species, reflecting differences
in the use of foraging habitat. The diving parameters also suggested that the on-shelf benthic layer was profitable foraging
habitat for gentoo penguins. Conversely, the relationship between trip duration, date, and stomach content mass suggested
that the chinstrap penguins went further from the colony to forage as the season progressed, possibly reflecting a reduction
in prey availability near the colony. Our results suggest that chinstrap and gentoo penguins segregated their foraging habitat
in the Antarctic coastal marine environment, possibly due to inter- and intra-specific competition for common prey resources. 相似文献
244.
Biodegradability of degradable plastics exposed to anaerobic digested sludge and simulated landfill conditions 总被引:3,自引:0,他引:3
The biodegradabilities of various plastics by anaerobic digested sludge were measured and compared with the biodegradabilities
under simulated landfill conditions. Bacterial poly(3-hydroxy-butyrate-co-3-hydroxyvalerate) (PHB/HV; 92/8, w/w), a natural
aliphatic polyester, degraded nearly to completion within 20 days of cultivation by anaerobic digested sludge, while synthetic
aliphatic polyesters such as poly-lactic acid, poly(butylene succinate), and poly (butylene succinate-co-ethylene succinate)
did not degrade at all in 100 days. Cellophane, which was used as a control material, exhibited a similar degradation behavior
to PHB/HV. Under simulated landfill conditions, PHB/HV degraded quite well within 6 months. Synthetic aliphatic polyesters
also showed significant weight losses through 1 year of cultivation. The acidic environment inside simulators generated by
the degradation of biodegradable food wastes which comprised 34 % of municipal solid waste seems to cause the weight loss
of synthetic aliphatic polyesters. 相似文献
245.
In this study,we investigated the effect of sample pretreatments(ultrasonication and alkaline extraction) on total organic carbon(TOC) measurements for water samples containing suspended solids(SS) of four different origins(algae,soil,sewage sludge,and leaf litter) to more clearly assess the impact of particulate organic carbon(POC) in water.The effects each of ultrasonication(power,pulse,etc.) and alkaline extraction condition(concentration,time,etc.) on the TOC recovery and precision were investigated,and the results were compared with those of a new sample pre treatment method combining both methods.Alkaline treatment(0.01 mol/L NaOH) showed higher precision than ultrasonication(100/5 on/off pulse),and notably,the differences among the measured TOC values in samples of different origins were also further reduced in the alkaline treatment.This suggests that the ultrasonic pretreatment results can be mainly attributed to the increase in POC recovery through particle size reduction,whereas the alkaline treatment results are achieved through the enhancement of POC solubilization.It is also particularly noteworthy that a higher TOC recovery of 87.6%±7.4% with a higher precision of 8.4%could be obtained using the combined method,compared to each treatment(ultrasonic:TOC recovery 34.7%,relative standard deviation 63.1%;alkaline:49.6% and 23.0%,respectively).Thus,simultaneous pretreatment with ultrasonication and alkaline extraction is expected to increase the oxidation rate of organic matter and the homogeneity of the samples,minimizing the loss of POC measurement values,and thereby improving the reliability of the TOC measurements of water samples containing SS. 相似文献
246.
Juntaek Lim Seung Gu Shin Seungyong Lee Seokhwan Hwang 《Frontiers of Environmental Science & Engineering in China》2011,5(1):28-39
Real-time quantitative polymerase chain reaction (qPCR) has gained popularity as a technique to detect and quantify a specific
group of target microorganisms from various environmental samples including soil, water, sediments, and sludge. Although qPCR
is a very useful technique for nucleic acid quantification, accurately quantifying the target microbial group strongly depends
on the quality of the primer and probe used. Many aspects of conducting qPCR assays have become increasingly routine and automated;
however, one of the most important aspects, designing and selecting primer and probe sets, is often a somewhat arcane process.
In many cases, failed or non-specific amplification can be attributed to improperly designed primer-probe sets. This paper
is intended to provide guidelines and general principles for designing group-specific primers and probes for qPCR assays.
We demonstrate the effectiveness of these guidelines by reviewing the use of qPCR to study anaerobic processes and biologic
nutrient removal processes. qPCR assays using group-specific primers and probes designed with this method, have been used
to successfully quantify 16S ribosomal Ribonucleic Acid (16S rRNA) gene copy numbers from target methanogenic and ammonia-oxidizing
bacteria in various laboratory- and full-scale biologic processes. Researchers with a good command of primer and probe design
can use qPCR as a valuable tool to study biodiversity and to develop more efficient control strategies for biologic processes. 相似文献
247.
248.
Katsuhisa Baba Akira Miyazono Keiji Matsuyama Shoui Kohno Shin Kubota 《Marine Biology》2007,151(5):1977-1987
In November 2003, we first observed prevalent occurrence of a hydroid, Eutima japonica, on soft body tissues of age zero Japanese scallop (Mizuhopecten yessoensis) juveniles cultured in large areas of Funka Bay, Hokkaido. The occurrence coincided with massive death of juvenile scallops.
A major objective was to clarify ecological relationships between the symbionts, and to infer the relationship between symbiosis
and the massive mortality. To do this, we investigated distributions of association rates of hydroids with juvenile scallops
at 15–34 sites over 3 years (2003–2005), with age one adult scallops at 24 sites in 2003, and with mussels at 13 sites in
2004. We studied seasonal changes in association rates with juvenile scallops, and numbers of polyps per juvenile scallop
at three sites from November 2003 to June 2004. We also quantified the hydroid impacts on juvenile scallop shell length growth
and triglyceride accumulation in the digestive gland. The association rate of E. japonica polyps with juvenile scallops was high in large areas of Funka Bay in 2003, and overlapped the distribution of mussels bearing
polyps. Association rates with age one adult scallops were very low in November 2003, even at the sites where polyps were
very common on juvenile scallops. Levels of hydroid occurrence in juvenile scallops varies by year. We found that hydroids
presence in juvenile scallops declined drastically in 2004 and 2005. The association rates with juvenile scallops, and numbers
of polyps per juvenile scallop declined during winter, until they disappeared completely in the following June. Since polyps
were rare in adult scallops, we believe that infection of juvenile scallops was probably initiated from the planulae produced
by medusae released from polyps growing on Mytilus spp., especially M. galloprovincialis. Subsequently, the inhabitation spread intraspecifically and interspecifically. In juvenile scallops, inhabitation of polyps
reduced shell length growth by 43%, and triglyceride accumulation in digestive glands by 24–47%. Inhabitation of E. japonica on juvenile scallop is best regarded as parasitism, rather than inquilinism or commensalism. Occurrence of polyps was probably
not a direct lethal factor for juvenile scallops, because there were some sites where association rates were high, but mortalities
were low. Massive mortalities in 2003 may have resulted from simultaneous impacts of heavy polyp load and stresses caused
by the way in which the animals were handled (transferred from cages for pre-intermediate culture to cages for intermediate
culture), because the massive mortality occurred within a month of the transfer. The presence of polyps in juvenile scallops
does not affect the quality of the product in Funka Bay, because market size scallops are hydroid-free. 相似文献
249.
250.
The Kumamoto oyster (Crassostrea sikamea) shows a spatially restricted distribution, favoring estuarine tideland environment. On the other hand, the Pacific oyster (C. gigas) has a broader range of habitat. The present study compared the mitochondrial population structure between the two closely related species. For accurate species identification of oysters sampled from Japanese and East Asian continental coasts, we performed sequencing analysis of the mitochondrial DNA (mtDNA) and PCR-RFLP assay of the first internal transcribed spacer of nuclear rRNA genes. Then, we estimated the extent of population differentiation within each of C. sikamea and C. gigas based on the mtDNA data. Few haplotypes were shared among the sites of sampling in C. sikamea, which contrasted with an extensive haplotype sharing among C. gigas samples. We discuss the mechanisms of elevated population differentiation observed in C. sikamea in light of the ecology and the ancient ocean geography around the present-day habitats. 相似文献